From cc809a441d8f2924f785eb863dfa6aef47a25b0b Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Tue, 12 Aug 2014 20:49:27 +0200
Subject: [PATCH 30/36] GPIO: add named gpio exports

Signed-off-by: John Crispin <blogic@openwrt.org>
---
 drivers/gpio/gpiolib-of.c     |   68 +++++++++++++++++++++++++++++++++++++++++
 drivers/gpio/gpiolib.c        |   11 +++++--
 include/asm-generic/gpio.h    |    5 +++
 include/linux/gpio/consumer.h |    8 +++++
 4 files changed, 90 insertions(+), 2 deletions(-)

--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -23,6 +23,8 @@
 #include <linux/pinctrl/pinctrl.h>
 #include <linux/slab.h>
 #include <linux/gpio/machine.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
 
 #include "gpiolib.h"
 
@@ -450,3 +452,73 @@ void of_gpiochip_remove(struct gpio_chip
 	gpiochip_remove_pin_ranges(chip);
 	of_node_put(chip->of_node);
 }
+
+#ifdef CONFIG_GPIO_SYSFS
+
+static struct of_device_id gpio_export_ids[] = {
+	{ .compatible = "gpio-export" },
+	{ /* sentinel */ }
+};
+
+static int __init of_gpio_export_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct device_node *cnp;
+	u32 val;
+	int nb = 0;
+
+	for_each_child_of_node(np, cnp) {
+		const char *name = NULL;
+		int gpio;
+		bool dmc;
+		int max_gpio = 1;
+		int i;
+
+		of_property_read_string(cnp, "gpio-export,name", &name);
+
+		if (!name)
+			max_gpio = of_gpio_count(cnp);
+
+		for (i = 0; i < max_gpio; i++) {
+			unsigned flags = 0;
+			enum of_gpio_flags of_flags;
+
+			gpio = of_get_gpio_flags(cnp, i, &of_flags);
+
+			if (of_flags == OF_GPIO_ACTIVE_LOW)
+				flags |= GPIOF_ACTIVE_LOW;
+
+			if (!of_property_read_u32(cnp, "gpio-export,output", &val))
+				flags |= val ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
+			else
+				flags |= GPIOF_IN;
+
+			if (devm_gpio_request_one(&pdev->dev, gpio, flags, name ? name : of_node_full_name(np)))
+				continue;
+
+			dmc = of_property_read_bool(cnp, "gpio-export,direction_may_change");
+			gpio_export_with_name(gpio, dmc, name);
+			nb++;
+		}
+	}
+
+	dev_info(&pdev->dev, "%d gpio(s) exported\n", nb);
+
+	return 0;
+}
+
+static struct platform_driver gpio_export_driver = {
+	.driver		= {
+		.name		= "gpio-export",
+		.owner	= THIS_MODULE,
+		.of_match_table	= of_match_ptr(gpio_export_ids),
+	},
+};
+
+static int __init of_gpio_export_init(void)
+{
+	return platform_driver_probe(&gpio_export_driver, of_gpio_export_probe);
+}
+device_initcall(of_gpio_export_init);
+
+#endif
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -122,6 +122,12 @@ static inline int gpio_export(unsigned g
 	return gpiod_export(gpio_to_desc(gpio), direction_may_change);
 }
 
+int __gpiod_export(struct gpio_desc *desc, bool direction_may_change, const char *name);
+static inline int gpio_export_with_name(unsigned gpio, bool direction_may_change, const char *name)
+{
+	return __gpiod_export(gpio_to_desc(gpio), direction_may_change, name);
+}
+
 static inline int gpio_export_link(struct device *dev, const char *name,
 				   unsigned gpio)
 {
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -427,6 +427,7 @@ static inline struct gpio_desc *devm_get
 
 #if IS_ENABLED(CONFIG_GPIOLIB) && IS_ENABLED(CONFIG_GPIO_SYSFS)
 
+int _gpiod_export(struct gpio_desc *desc, bool direction_may_change, const char *name);
 int gpiod_export(struct gpio_desc *desc, bool direction_may_change);
 int gpiod_export_link(struct device *dev, const char *name,
 		      struct gpio_desc *desc);
@@ -434,6 +435,13 @@ void gpiod_unexport(struct gpio_desc *de
 
 #else  /* CONFIG_GPIOLIB && CONFIG_GPIO_SYSFS */
 
+static inline int _gpiod_export(struct gpio_desc *desc,
+			       bool direction_may_change,
+			       const char *name)
+{
+	return -ENOSYS;
+}
+
 static inline int gpiod_export(struct gpio_desc *desc,
 			       bool direction_may_change)
 {
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -544,7 +544,7 @@ static struct class gpio_class = {
  *
  * Returns zero on success, else an error.
  */
-int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
+int __gpiod_export(struct gpio_desc *desc, bool direction_may_change, const char *name)
 {
 	struct gpio_chip	*chip;
 	struct gpiod_data	*data;
@@ -604,6 +604,8 @@ int gpiod_export(struct gpio_desc *desc,
 	offset = gpio_chip_hwgpio(desc);
 	if (chip->names && chip->names[offset])
 		ioname = chip->names[offset];
+	if (name)
+		ioname = name;
 
 	dev = device_create_with_groups(&gpio_class, chip->dev,
 					MKDEV(0, 0), data, gpio_groups,
@@ -625,6 +627,12 @@ err_unlock:
 	gpiod_dbg(desc, "%s: status %d\n", __func__, status);
 	return status;
 }
+EXPORT_SYMBOL_GPL(__gpiod_export);
+
+int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
+{
+	return __gpiod_export(desc, direction_may_change, NULL);
+}
 EXPORT_SYMBOL_GPL(gpiod_export);
 
 static int match_export(struct device *dev, const void *desc)
